Pages

Thursday, December 19, 2013

Astronomers May Have Found the First-Ever Exomoon

Astronomers at University of Notre Dame, Indiana claim they have seen the human race’s first-ever exomoon, and it seems weirder than we ever could have imagined. MOA-2011-BLG-262 is the shortest duration microlensing event to date with a planetary mass companion, and the lens-source relative proper motion is unusually high. The high relative proper motion suggests a nearby lens, but if this is the case, then the primary must have a mass of a few Jupiter masses. This would imply that the secondary is an exomoon of about an Earth mass. The other alternative is that the velocity of the planet host star is quite large, implying that it resides in the Milky Way's halo.

Exomoons have long been predicted to exist – some may even be habitable worlds – but until now, no one had detected any. "This is the first serious candidate from any survey that I am aware of," says astronomer David Kipping of Harvard University, who was not involved in the discovery.

Most of the 1000 or so exoplanets discovered to date were found by analysing changes in the light of their star, but a select few have been seen using a technique called gravitational microlensing. When an object passes in front of a distant star as seen from Earth, the object's gravity bends the light from the background star, focusing it like a lens – and making the star temporarily appear brighter if observed from a particular angle.

The planet and moon, located 1,800 light years from Earth, are around four times the mass of Jupiter, and half the mass of Earth, respectively.

In a paper posted online earlier this week, David Bennett of the University of Notre Dame, Indiana, and colleagues report that they spotted a microlensing event in 2011, using a number of telescopes around the world. First they saw the distant star's light amplified to 70 times its normal brightness. An hour later came a second, smaller increase in brightness.

That suggests that a large object passed in front of the star, followed by a smaller one. However, it is unclear whether these two objects are a planet and its moon as the team came up with two possible scenarios that fit the microlensing data.

In the other scenario, the pair of objects is much further away and consists of a very small star or a failed star known as a brown dwarf, orbited by a Neptune-mass planet.

Unfortunately, there isn’t yet a way to tell whether or not the two bodies are a planet and its moon, or a failed star and a planet. So, we won’t know for some time if the human race just saw its first exomoon, but there is a decent chance.

If you are facing the McAfee email account recovery issues, or it’s any relevant, then you need to get the support of McAfee customer service number +1 (888) 995-4664. For obtaining their direct official number, you need to visit at: http://www.mcafeetechnicalsupportnumber.com/scan-support.php please don’t hesitate.